The present invention relates to a heat-seal type wrapping apparatus and more particularly to a heat-seal type wrapping apparatus which operates by forming a long plastic film into a cylinder while unwinding it from a reel, wrapping successive articles, such as pieces of candy, at regular intervals in the plastic film which is being cylindrically formed, continuously heat-sealing the plastic film, and severing the cylinder of plastic film into separate heat-sealed packages.
As for a wrapping apparatus adapted to wrap articles in a film which is being formed into a cylinder and seal said film by a heat-sealing device, mention may be made, for example, of U.S. Pat. Nos. 2,260,046 and 2,886,930.
As for wrapping materials used in such heat-seal type wrapping apparatus, plastic films are generally used. Plastic films, though featuring low wrapping cost, have poor heat sealability such that quick heating often fails to provide a satisfactorily heat seal. For this reason, automatic wrapping apparatuses of this type have heretofore been operated at low speed for heat sealing, which is inefficient.
Further, ordinary automatic wrapping apparatuses have been designed on the assumption that the size of articles to be wrapped is constant or that the length of packages is constant. Therefore, when the size of articles to be wrapped or the length of packages is changed, it is necessary to change the speeds of conveyors for feeding a plastic film and articles to be wrapped and change the rotative speed of the transversely heat-sealing device, such changes involving troublesome adjustments.